Ionic Liquids: Solvent Replacement in Cleaning Operations

Many industrial solvents used in cleaning operations produce greenhouse gases (GHGs) and contain volatile organic compounds (VOCs), hazardous air pollutants (HAPs), and/or ozone-depleting substances (ODSs).  HAP and ODS concerns have been addressed previously with less harmful replacement candidates being identified; however, some replacements still contain VOCs or GHGs.  Ionic liquids (IL) may offer potential as more environmentally friendly replacements for commonly used organic solvents.

 Three candidates, 2-ethylhexyl lactate (2ehl), 1-ethyl-3-methylimidazolium (EMIM) acetate and EMIM ethylsulfate, were identified as having the potential to be used as cleaning agents, and were tested according to quality testing procedures currently performed at U.S. Air Force Air Logistics Complexes and military cleaning specifications.  Baseline chemicals, n-propyl bromide (nPB) and hydrofluoroether (HFE) 7100, also were tested.  Test results related to cleaning efficiency and chemical compatibility with representative substrates will be presented.